The 87-year-old baroness had spent Christmas in a Central London hospital after being admitted earlier this month.

According to BBC, Thatcher was doing well and left the hospital yesterday to "convalesce privately."

It is, however, not clear whether she is now at home.

The former Conservative leader was said to be 'doing well' after the minor operation.

"She's very tough. The doctors are perfectly happy. They say the operation has been completely satisfactory," former adviser and friend, Lord Bell was quoted by BBC News as saying, following her operation.

Earlier last week, the British Prime Minister David Cameron had tweeted a message to Thatcher after her admission, wishing her a 'speedy recovery'.

Thatcher was the UK's first female prime minister and served three terms, between 1979 and 1990.

The veteran ex-premier's public appearances have been very restricted over recent years due to continued ill health.

Her health was thrust into the global spotlight this year when Meryl Streep starred in a controversial Hollywood film about her.

The Iron Lady drew criticism from Cameron and others for concentrating on the dementia she has suffered after a series of small strokes.

Meryl Streep won an Oscar for the role.

Her daughter, Carol Thatcher, has previously spoken of her mother's struggle with dementia.